![Page 1: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/1.jpg)
ENV 2006 10.1
Envisioning Information
Lecture 10 – Cartograms: A different way of drawing maps
![Page 2: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/2.jpg)
ENV 2006 10.2
Choropleth Maps
• Maps have been traditionally drawn to represent area
– With topography indicated by shading
• Increasingly we use maps to represent properties about areas
– Here each state is shaded according to density of population
– Known as choropleth mapping
http://www.cdc.noaa.gov/USclimate/states.fast.html
![Page 3: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/3.jpg)
ENV 2006 10.3
Discuss Strengths and Weaknesses
• Strengths • Weaknesses
![Page 4: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/4.jpg)
ENV 2006 10.4
Cartograms
• The cartogram is a response to these issues
– Rather than accurately reflect the area and superimpose shading to represent the variable..
– .. Distort the area so as to reflect the variable directly
![Page 5: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/5.jpg)
ENV 2006 10.5
Types of Cartogram
• Cartograms can be contiguous or non-contiguous
– Here is population of California by county as a contiguous cartogram
![Page 6: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/6.jpg)
ENV 2006 10.6
Types of Cartogram
• .. And now as a non-contiguous cartogram
![Page 7: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/7.jpg)
ENV 2006 10.7
Contiguous and Non-Contiguous Cartograms
• Here is the US population example in both styles…
![Page 8: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/8.jpg)
ENV 2006 10.8
Perimeter-preservation
![Page 9: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/9.jpg)
ENV 2006 10.9
World Population Cartogram
Acknowledgement: Examples taken from Web site of Dr Donald Househttp://www-viz.tamu.edu/faculty/house/cartograms
![Page 10: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/10.jpg)
ENV 2006 10.10
George Bush – Victory large or small?
![Page 11: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/11.jpg)
ENV 2006 10.11
Types of Cartogram
• Danny Dorling (recently Professor in Leeds) invented a special type of cartogram using circles of different size
http://www.ncgia.ucsb.edu/projects/Cartogram_Central/index.html
![Page 12: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/12.jpg)
ENV 2006 10.12
Dorling Cartograms
• Try the applet at:http://www.mapresso.com/dorling/dorlingexample.html
![Page 13: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/13.jpg)
ENV 2006 10.13
British county populations evolving…
![Page 14: Envisioning Information Lecture 10 – Cartograms: A different way of drawing maps](https://reader035.vdocuments.site/reader035/viewer/2022062315/56815d91550346895dcba949/html5/thumbnails/14.jpg)
ENV 2006 10.14
Chernoff Face Cartogram!
• Acknowledgement:– Last two slides from
‘Cartograms for Human Geography’, by D. Dorling, in Visualization in Geographical Information Systems, Wiley.